C#

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
    var connectionString = @"Server=MAROIS_KEVIN_1\SQLEXPRESS;Database=Test;User Id=FatALbert;Password=AlbertIsFat!;;Encrypt=false;";
    optionsBuilder.UseSqlServer(connectionString, options => options.EnableRetryOnFailure());
}

Microsoft.EntityFrameworkCore.Storage.RetryLimitExceededException
  HResult=0x80131500
  Message=The maximum number of retries (6) was exceeded while executing database operations with 'SqlServerRetryingExecutionStrategy'. See the inner exception for the most recent failure.
  Source=Microsoft.EntityFrameworkCore
  StackTrace:
   at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.ExecuteImplementation[TState,TResult](Func`3 operation, Func`3 verifySucceeded, TState state)
   at Microsoft.EntityFrameworkCore.Storage.ExecutionStrategy.Execute[TState,TResult](TState state, Func`3 operation, Func`3 verifySucceeded)
   at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChanges(Boolean acceptAllChangesOnSuccess)
   at Microsoft.EntityFrameworkCore.DbContext.SaveChanges(Boolean acceptAllChangesOnSuccess)
   at Program.<Main>$(String[] args) in C:\Projects\SandBox\Learning\EF6Core\Database First\EFCoreDBFirstExample\Program.cs:line 11

  This exception was originally thrown at this call stack:
    [External Code]

Inner Exception 1:
SqlException: Cannot open database "Test" requested by the login. The login failed.
Login failed for user 'FatAlbert'.

using (var db = new ModelContext())
{
    // Update the database to the latest migration
    db.Database.Migrate();

    // Creating a new department and save it to the database
    var newDept = new Departments();
    newDept.DepartmentId = 1;
    newDept.DepartmentName = "Development";

public virtual DbSet<Department> Departments { get; set; }
public virtual DbSet<Employee> Employees { get; set; }

entity.ToTable("Employees", "public");

Applying migration '20221127185110_Initial'.
Failed executing DbCommand (2ms) [Parameters=[], CommandType='Text', CommandTimeout='30']
IF SCHEMA_ID(N'public') IS NULL EXEC(N'CREATE SCHEMA [public];');
Microsoft.Data.SqlClient.SqlException (0x80131904): There is already an object named 'public' in the database.
CREATE SCHEMA failed due to previous errors.
   at Microsoft.Data.SqlClient.SqlConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
   at Microsoft.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
   at Microsoft.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
   at Microsoft.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady)
   at Microsoft.Data.SqlClient.SqlCommand.RunExecuteNonQueryTds(String methodName, Boolean isAsync, Int32 timeout, Boolean asyncWrite)
   at Microsoft.Data.SqlClient.SqlCommand.InternalExecuteNonQuery(TaskCompletionSource`1 completion, Boolean sendToPipe, Int32 timeout, Boolean& usedCache, Boolean asyncWrite, Boolean inRetry, String methodName)
   at Microsoft.Data.SqlClient.SqlCommand.ExecuteNonQuery()
   at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteNonQuery(RelationalCommandParameterObject parameterObject)
   at Microsoft.EntityFrameworkCore.Migrations.MigrationCommand.ExecuteNonQuery(IRelationalConnection connection, IReadOnlyDictionary`2 parameterValues)
   at Microsoft.EntityFrameworkCore.Migrations.Internal.MigrationCommandExecutor.ExecuteNonQuery(IEnumerable`1 migrationCommands, IRelationalConnection connection)
   at Microsoft.EntityFrameworkCore.Migrations.Internal.Migrator.Migrate(String targetMigration)
   at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.UpdateDatabase(String targetMigration, String connectionString, String contextType)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabaseImpl(String targetMigration, String connectionString, String contextType)
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.UpdateDatabase.<>c__DisplayClass0_0.<.ctor>b__0()
   at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)
ClientConnectionId:5f3126d9-a1c8-4a81-b0f8-8eba5fd77448
Error Number:2714,State:6,Class:16
There is already an object named 'public' in the database.
CREATE SCHEMA failed due to previous errors.

Dave Kreskowiak wrote:

Where did you find this tutorial you're following?

Dave Kreskowiak wrote:

The problem with Linq-To-Sql is that it is a dead product and no longer under development.

dotnet ef migrations add AddCompanies
dotnet ef database update

Fezih5 wrote:

C#

PdfWriter pdfWriter = PdfWriter.GetInstance(document, new FileStream(path + originalFileName, FileMode.Append));

SELECT * FROM MyTable WHERE StreetAddress = 'Baker's Wood'

SELECT * FROM MyTable WHERE StreetAddress = 'x';DROP TABLE MyTable;--'

SELECT * FROM MyTable WHERE StreetAddress = 'x';

DROP TABLE MyTable;

--'

StringBuilder sb = new StringBuilder("INSERT INTO table VALUES (");
foreach (object value in ((IDictionary<string, object>)rec).Values)
{
    if (command.Parameters.Count != 0) sb.Append(", ");
    string name = "@V" + command.Parameters.Count;
    command.Parameters.AddWithValue(name, value);
    sb.Append(name);
}
sb.Append(");");

command.CommandText = sb.ToString();

StringBuilder columnsList = new StringBuilder();
StringBuilder valuesList = new StringBuilder();
foreach (KeyValuePair<string, object> item in (IDictionary<string, object>)rec)
{
    if (columnsList.Length != 0) columnsList.Append(", ");
    if (valuesList.Length != 0) valuesList.Append(", ");
    
    string name = "@" + item.Key;
    command.Parameters.AddWithValue(name, item.Value);
    columnsList.Append(item.Key);
    valuesList.Append(name);
}

command.CommandText = "INSERT INTO table (" + columnsList + ") VALUES (" + valuesList + ");";